Malicious PDF — malware analysis report

Static analysis result for SHA-256 658fe5fcdd7f1c6b…

MALICIOUS

PDF

83.8 KB Created: 2021-08-16 14:43:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: efa1a708bff62f55d4b11a78dd8f6b42 SHA-1: c7f8b3aa86ef5fba808cf4fb0c7b896a267cf8b7 SHA-256: 658fe5fcdd7f1c6b867b37eb5a392d1b4545473a001b53bbda3773a82189dec5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a malicious document, potentially leveraging embedded JavaScript for further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://synerhu.ru/uplcv?utm_term=exponential+and+logarithmic+functions+practice+test+pdf
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f40c17e4a5---nafotisudifirotifobiwo.pdf
    • http://xycrusher.com/d/files/limosazigiwejakilibijaf.pdf
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/89fcf5da8a1a4355ba4c4389602cd605/52009916605.pdf
    • https://ayurmitra.com/files/file/34922074897.pdf
    • http://www.srijonihealinghome.com/fckimages/file/24621109089.pdf
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/31e2e1058e73170a05ac98cd8916e383/81230785802.pdf
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609436aee46d7---mezesegesuxagedijegatin.pdf
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/c0dcc1c51fff66106ccd5c8172b03e17/xedubamifesi.pdf
    • http://khachsansapa.vn/webroot/img/files/43102390877.pdf
    • http://dfwarbitrator.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/binoxamedumi.pdf
    • http://whkmradio.com/userfiles/file/65747331415.pdf
    • https://www.alignerco.ca/wp-content/plugins/super-forms/uploads/php/files/e9f237303b20d2fb680b7fa92c9a8915/mosikatitarejilajav.pdf
    • https://consultingexpert.eu/fckeditor/userfiles/file/zenepesimisozabigugavujig.pdf
    • https://vinniescustoms.com/userfiles/files/kevesupoburefe.pdf
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160983ffd7d74d---veligawiseke.pdf
    • http://broadviewlibrary.org/uploaded_bvlib/file/romeworuxekelujemojumejup.pdf
    • http://omgmediatank.com/userfiles/files/kitejixotegawilu.pdf
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/a0453f74e59b29d88809b4025414afab/69528521738.pdf
    • http://zap-interactive.com/uploads/files/pivoka.pdf
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/6c83ed9572ffb37bc2ed1aa37c509470/zidukumiri.pdf
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16092409fc6561---52962575416.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073666377759---wotulirolonowuxenowofameb.pdf
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c52a6cb57bb---60442992934.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000deba.bin
d11fb13e21fa44c4840638365bf8e0dc598babbf4fcd92593bf892d3530f52b7
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBA 17812 bytes
font_01_sfnt_off00010db2.bin
6eee749107b78831dfe2691040a79016fc20a192c606926d0a931bf551316ef1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB2 11252 bytes
font_02_sfnt_off000127b0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x127B0 16792 bytes